X-Rays with Receiving Tubes

Posted on Aug 12, 2012

Old TV tubes are used as cold cathode x-ray emitters in a simple apparatus developed by Bob Templeman of Chicago, Illinois. With selected beam power tubes of the type used in the high voltage section of TV receivers, the intensity is adequate to make x-rays photographs of objects using standard films. The earliest x-ray tubes were of the cold cathode variety. These tubes, referred to as Crookes or Hittorf tubes, were of the general class of gas tubes since the pressure had to be in the ‘soft’ vacuum range (about 10-3 to 10-4 Torr) to permit the passage of electrons from the cathode to the x-ray producing target in a so-called ‘dark’ discharge.

Click here to download the full size of the above Circuit.

Higher pressures would result in a luminous discharge (as in a neon lamp) with only a small potential drop across the tube. Lower pressures (a 'hard' vacuum) would result in no current flow regardless of applied voltage. The cold cathode tube went out of use shortly after 1910 when W. D. Coolidge introduced a tube with a hot cathode (thermionic) electron emitter. The Coolidge tube, which uses high vacuum (typically below 10-5 Torr), has a number of advantages over the gas tube. With the gas tube, the electron current, at a given voltage, is dependent the voltage across the tube which, in turn, can vary depending upon the degree of vacuum. Furthermore, the degree of vacuum will change over time. This will affect the spectrum (hence the penetrating quality) of the x-ray output as well as the intensity. With a heated cathode in a high vacuum tube, the electron current may be controlled simply by varying the filament temperature. Then, by varying the voltage across the tube, the penetrating power of the x-rays (a function of the x-ray energy) may be varied. Thus, two important parameters may be controlled independently. Bob Templeman has been able to use conventional vacuum tubes as cold cathode x-ray tubes. He has done most of his work with the 6BK4B, a beam triode used for voltage regulation of high voltage, low current dc power supplies in color and black-and-white television sets. The tube has an octal base and a...

Visit page

Leave Comment

characters left:

New Circuits

Zero consumption Anti-theft High power Code Switch for E-Bike Batteries

This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
Ultrasonic distance finder circuit

The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Simple Metal detector circuit with CD4030

Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Fully automatic watering circuit for flower pots

Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
Simple deep searching metal detector circuit

The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
Sub-Harmonic Bass Converter for Electric Guitars

The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
Echo Depth Sounding Sonar for Boats

In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
100W HiFi Audio Amplifier Circuit

This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
Plant-Pot Water Level Indicator Circuit

A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....

Create NOW your QR MENU for your Restaurant / Hotel / Bar / Caffe,

Comprehensive ordering/paying features. fully personalized to suit your Business.

Update Anytime! Easy and Simple!

Popular Circuits

CDI Capacitor Discharge Ignition Circuit

The CDI ignition circuit produces a spark from an ignition coil by discharging a capacitor across...

stepper motor controller circuit

The circuit shown above can be used to control a unipolar stepper motor which has FOUR coils...

OP37 low noise microphone preamp circuit design electronic project

This microphone preamp schematic electronic circuit project is designed using the OP37...

electronic door buzzer circuit schematic

This electronic door buzzer circuit schematic has a very simple function and is very easy to...

Power Supply For USB Devices

More and more equipment is sold that runs off internal rechargeable batteries. Although a...

A CMOS the spot welding time adjustment circuit b

A CMOS constituting the spot welding time adjustment circuit b The number of cycles it uses CMOS...

IC audio power amplifier circuit

Due to the rapid development of integrated circuit technology, an integrated circuit amplifier...